iPlayer - hit and miss?

Is anyone else having this trouble in XBMC: I’m running through my UK proxy and about 1/4-1/3 of the listed BBC shows are working.  Which are genuinely odd - eg, on the BBC2 channel I can play Match of the Day, Great British Food Revival, Secret Pakistan, Top Gear…but not the other 6 items. BBC1, also about 1/3 - Frozen Planet, Rhod Gilbert, League Cup show, but not Eastenders, Death in Paradise, etc… I can get the Impression Show but not Strictly catchup - so there’s no accounting for taste either. 

Checking the logs, my proxy is passing fine - I just seem to hit files that are generating errors: 

ERROR: Playlist Player: skipping unplayable item: 0, path [rtmp://cp41752.edgefcs.net:1935/ondemand?auth=daEcDcEbxdvd2aydEbqc0dvbddQaybCa3aB-boQEsB-bWG-KplEDqxqJBrHnxI&aifp=v001&slist=secure/800kbps/MP/b016mw1z_1319684192.mp4;secure/1500kbps/MP/b016mw1z_1319683917.mp4;secure/480kbps/MP/b016mw1z_1319684184.mp4;secure/400kbps/b016mw1z_1319684186.mp4 playpath=mp4:secure/1500kbps/MP/b016mw1z_1319683917.mp4 swfurl=http://www.bbc.co.uk/emp/10player.swf swfvfy=true timeout=180]

16:09:17 T:135909376 M:114847744   DEBUG: Playlist Player: no more playable items… aborting playback

I'm not sure if it's a common problem, an access problem, an availability issue (too many active streams) or whatnot - anyone else having this issue?